J2EE Interview Questions/ Answer Set-2

  11. What is the web container?

 Ans:  - Servlet and JSP containers are collectively referred to as Web containers. It manages the execution of JSP page and servlet components for J2EE applications. Web components and their container run on the J2EE server.

  12. What is Enterprise JavaBeans (EJB) container?

Ans:  - It manages the execution of enterprise beans for J2EE applications.

      Enterprise beans and their container run on the J2EE server.

  13. What is Applet container?

Ans:  - It manages the execution of applets. It consists of a Web browser and Java Plug-in running on the client together.

  14. How do we package J2EE components?

Ans:  - J2EE components are packaged separately and bundled into a J2EE application for deployment. Each component, its related files such as GIF and HTML files or server-side utility classes, and a deployment descriptor are assembled into a module and added to the J2EE application. A J2EE application is composed of one or more enterprise bean, Web, or application client component modules. The final enterprise solution can use one J2EE application or be made up of two or more J2EE applications, depending on design requirements. A J2EE application and each of its modules has its own deployment descriptor. A deployment descriptor is an XML document with an .xml extension that describes a component’s deployment settings.

  15. What is a thin client?

Ans:  - A thin client is a lightweight interface to the application that does not have such operations like query databases, execute complex business rules, or connect to legacy applications.

  16. What are types of J2EE clients?

Ans:   - Following are the types of J2EE clients:

          * Applets

          * Application clients

          * Java Web Start-enabled rich clients, powered by Java Web Start technology.

          * Wireless clients, based on Mobile Information Device Profile (MIDP) technology.

  17. What is deployment descriptor?

Ans:   - A deployment descriptor is an Extensible Markup Language (XML) text-based file with an .xml extension that describes a component’s deployment settings. A J2EE application and each of its modules has its own deployment descriptor. For example, an enterprise bean module deployment descriptor declares transaction attributes and security authorizations for an enterprise bean. Because deployment descriptor information is declarative, it can be changed without modifying the bean source code. At run time, the J2EE server reads the deployment descriptor and acts upon the component accordingly.

  18. What is the EAR file?

 Ans:  - An EAR file is a standard JAR file with an .ear extension, named from Enterprise Archive file. A J2EE application with all of its modules is delivered in EAR file.